The present invention discloses a papermaking black liquor treatment process. It is characterized by that it includes a black liquor storage tank, said black liquor storage tank is connected with a reaction storage tank by adopting pipeline, between the black liquor storage tank and reaction storage tank a chemicals tank is set, said reaction storage tank is connected with a pressure tank, said pressure tank is connected with a plate-frame pressure filter, said plate-frame pressure filter is connected with a stirring chamber, said stirring chamber is connected with a feeding machine, said feeding machine is connected with a feeding pump, said feeding pump is connected with a boiler, the above-mentioned plate-frame pressure filter is connected with a filtrate tank, said filtrate tank is connected with a reactor, said reactor is connected with a first precipitation tank and its first chemicals liquor storage tank is connected with the pipeline positioned between the reactor and filtrate tank by means of pipeline. |